Aluminum extrusion with low carbon footprint

ABSTRACT

An alloy composition is provided. The alloy composition includes from about 0.5 wt. % to about 1.5 wt. % silicon (Si), from about 0.5 wt. % to about 1.5 wt. % magnesium (Mg), from about 0.1 wt. % to about 0.2 wt. % zirconium (Zr), from about 0.2 wt. % to about 0.4 wt. % iron (Fe), from 0 wt. % to about 0.3 wt. % chromium (Cr), from 0 wt. % to about 0.3 wt. % manganese (Mn), from about 0 wt. % to about 1 wt. % copper (Cu), from about 0 wt. % to about 0.2 wt. % titanium (Ti), from about 0 wt. % to about 1 wt. % vanadium (V), and a balance of aluminum (Al). Greater than or equal to about 60% of the alloy composition is derived from Al scrap. Methods of forming the alloy composition and methods of forming an extruded article from the composition are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit and priority of Chinese ApplicationNo. 202110606973.X, filed Jun. 1, 2021. The entire disclosure of theabove application is incorporated herein by reference.

INTRODUCTION

This section provides background information related to the presentdisclosure which is not necessarily prior art.

Components made of aluminum (Al) alloys have become ever more prevalentin various industries and applications, including general manufacturing,construction equipment, automotive or other transportation industries,home or industrial structures, aerospace, and the like. For example, Alalloys are used in manufacturing industries for extruding parts thathave uniform cross-sectional geometries or are made from parts havinguniform cross-sectional geometries. In particular, 6000 series Al alloyscan be processed by extrusion, heat treatment, and/or welding andexhibit high strength and corrosion resistance. With thesecharacteristics, 6000 series Al alloys are suitable for automotiveapplications.

6000 series Al alloys include at least about 70 wt. % primary Al. Themanufacture of primary Al from bauxite ore results in about 15-22 tonsof carbon dioxide (CO₂) emission per ton of primary Al produced.Increased usage of Al scrap in the manufacturing of Al extrusion willreduce the carbon (C) footprint significantly because CO₂ emissionassociated with the pre-processing and re-melting of Al scrap is onlyabout 5% of the CO₂ emission associated with primary Al production.However, the content of iron (Fe) impurities in Al scrap may be muchhigher than the content of Fe content in 6000 series Al alloys used inautomotive Al extrusion, which is detrimental to fracture toughness andcrash performance of the final product. Therefore, it would bebeneficial to develop an Al alloy having a relatively high tolerance toFe impurities and that exhibits high strength and fracture resistance.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

The present disclosure relates to Al extrusions with a low C footprint.

In various aspects, the current technology provides an alloy compositionincluding silicon (Si) at a concentration of greater than or equal toabout 0.5 wt. % to less than or equal to about 1.5 wt. %, magnesium (Mg)at a concentration of greater than or equal to about 0.5 wt. % to lessthan or equal to about 1.5 wt. %, zirconium (Zr) at a concentration ofgreater than or equal to about 0.1 wt. % to less than or equal to about0.2 wt. %, Fe at a concentration of greater than or equal to about 0.2wt. % to less than or equal to about 0.4 wt. %, chromium (Cr) at aconcentration of greater than or equal to about 0 wt. % to less than orequal to about 0.3 wt. %, manganese (Mn) at a concentration of greaterthan or equal to about 0 wt. % to less than or equal to about 0.3 wt. %,copper (Cu) at a concentration of greater than 0 wt. % to less than orequal to about 1 wt. %, titanium (Ti) at a concentration of greater than0 wt. % to less than or equal to about 0.2 wt. %, vanadium (V) at aconcentration of greater than 0 wt. % to less than or equal to about 0.2wt. %, and a balance of the alloy composition being Al.

In one aspect, the alloy composition includes the Si at a concentrationof greater than or equal to about 0.7 wt. % to less than or equal toabout 1 wt. %, the Mg at a concentration of greater than or equal toabout 0.7 wt. % to less than or equal to about 1 wt. %, and the Zr at aconcentration of greater than or equal to about 0.12 wt. % to less thanor equal to about 0.17 wt. %.

In one aspect, the alloy composition includes at least one of the Cr ata concentration of greater than or equal to about 0.05 wt. % to lessthan or equal to about 0.3 wt. % or the Mn at a concentration of greaterthan or equal to about 0.05 wt. % to less than or equal to about 0.3 wt.%.

In one aspect, the alloy composition includes the Cr at a concentrationof greater than or equal to about 0.1 wt. % to less than or equal toabout 0.25 wt. % and the Mn at a concentration of greater than or equalto about 0.1 wt. % to less than or equal to about 0.25 wt. %, whereinthe combined concentration of the Cr and the Mn is less than or equal toabout 0.45 wt. %.

In one aspect, the alloy composition has a first dispersoid including Zrand at least one of Si or Al and a second dispersoid including Si, Fe,Al, and at least one of Cr or Mn, wherein the first and seconddispersoids have individual diameters of greater than or equal to about30 nm to less than or equal to about 100 nm.

In one aspect, the alloy composition includes a reduced amount ofintermetallic phases including Fe relative to a comparative 6082 alloycomposition having substantially the same Fe concentration.

In one aspect, greater than or equal to about 60% of the alloycomposition is derived from post-consumer Al scrap.

In one aspect, the alloy composition is in the form of a billet or alog.

In one aspect, the alloy composition is in the form of an extrudedarticle having a fibrous structure defined by the alloy composition.

In one aspect, the extruded article is an automobile part selected fromthe group consisting of a beam, bumper, a floor pan, a batteryenclosure, a wheel, a rocker, a control arm, a rail, a reinforcementpanel, a step, a subframe member, a pillar, and a strut.

In one aspect, the extruded article has a yield strength of greater thanor equal to about 280 MPa and an elongation to fracture of greater thanor equal to about 8%.

In various aspects, the current technology also provides a method offorming an extruded article, the method including heating a billethaving an alloy composition to a temperature of greater than or equal toabout 450° C. to less than or equal to about 550° C. to form a heatedbillet, extruding the heated billet through a die to form a heatedextruded article, and quenching the heated extruded article to form theextruded article, the extruded article having a fibrous structuredefined by the alloy composition, wherein the alloy composition includesSi at a concentration of greater than or equal to about 0.5 wt. % toless than or equal to about 1.5 wt. %, Mg at a concentration of greaterthan or equal to about 0.5 wt. % to less than or equal to about 1.5 wt.%, Zr at a concentration of greater than or equal to about 0.1 wt. % toless than or equal to about 0.2 wt. %, Fe at a concentration of greaterthan or equal to about 0.2 wt. % to less than or equal to about 0.4 wt.%, Cr at a concentration of greater than or equal to about 0 wt. % toless than or equal to about 0.3 wt. %, Mn at a concentration of greaterthan or equal to about 0 wt. % to less than or equal to about 0.3 wt. %,Cu at a concentration of greater than 0 wt. % to less than or equal toabout 1 wt. %, Ti at a concentration of greater than 0 wt. % to lessthan or equal to about 0.2 wt. %, V at a concentration of greater than 0wt. % to less than or equal to about 0.2 wt. %, and a balance of thealloy composition being Al.

In one aspect, greater than or equal to about 60% of the alloycomposition is derived from post-consumer Al scrap.

In one aspect, the alloy composition has a first dispersoid including Zrand at least one of Si or Al and a second dispersoid including Si, Fe,Al, and at least one of Cr or Mn, wherein the first and seconddispersoids have individual diameters of greater than or equal to about30 nm to less than or equal to about 100 nm.

In one aspect, the extruding is performed with a ram at a ram speed ofgreater than or equal to about 4 ipm to less than or equal to about 20ipm.

In one aspect, the quenching is performed by water mist at a coolingrate of greater than or equal to about 0.05° C./s.

In one aspect, the method further includes aging the extruded article byheating the extruded article to a temperature of greater than or equalto about 120° C. to less than or equal to about 250° C. for a time ofgreater than or equal to about 0.5 hours to less than or equal to about20 hours.

In one aspect, prior to the heating, the alloy composition is subjectedto a homogenization process including heating the billet at a rate ofgreater than or equal to about 1° C./min to less than or equal to about10° C./min until the alloy composition reaches a temperature of greaterthan or equal to about 500° C. to less than or equal to about 580° C.,maintaining the alloy composition at the temperature for greater than orequal to about 0.5 hours to less than or equal to about 24 hours, andquenching the alloy composition.

In one aspect, the method generates less than or equal to about 10 tonsof C footprint per 1 ton of the extruded article that is formed.

In various aspects, the current technology further provides a method offorming an alloy composition, the method including forming a melt bymelting post-consumer Al scrap; adding at least one master alloy ingotto the melt, wherein the at least one master alloy ingot provides Si,Mg, Zr, Cr, Mn, Cu, Ti, and V; adding at least one primary Al ingot tothe melt to form an alloy melt, wherein the alloy melt includes theprimary Al ingot at a concentration of less than about 40 wt. % based onthe total mass of the alloy melt; casting the alloy melt in adirect-chilled tooling to form a casted alloy composition; andsolidifying the casted alloy composition to form the alloy composition,wherein the alloy composition includes Si at a concentration of greaterthan or equal to about 0.5 wt. % to less than or equal to about 1.8 wt.%, Mg at a concentration of greater than or equal to about 0.5 wt. % toless than or equal to about 1.5 wt. %, Zr at a concentration of greaterthan or equal to about 0.05 wt. % to less than or equal to about 0.2 wt.%, Fe at a concentration of greater than or equal to about 0.2 wt. % toless than or equal to about 0.4 wt. %, Cr at a concentration of greaterthan or equal to about 0 wt. % to less than or equal to about 0.3 wt. %,Mn at a concentration of greater than or equal to about 0 wt. % to lessthan or equal to about 0.3 wt. %, Cu at a concentration of greater than0 wt. % to less than or equal to about 1 wt. %, Ti at a concentration ofgreater than 0 wt. % to less than or equal to about 0.2 wt. %, V at aconcentration of greater than 0 wt. % to less than or equal to about 0.2wt. %, and a balance of the alloy composition being Al.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is an illustration showing a cross-section of an exemplaryas-cast 6000 series Al alloy billet. The scale bar is 30 μm.

FIG. 2A is an illustration of a comparative as-cast Al alloy billethaving dispersoids embedded within a matrix. The scale bar is 0.2 μm.

FIG. 2B is an illustration of an exemplary comparative extruded articleformed from the comparative as-cast Al alloy billet of FIG. 2A. Thescale bar is 1000 μm.

FIG. 3A is an illustration of an as-cast Al alloy billet havingdispersoids embedded within a matrix in accordance with various aspectsof the current technology. The scale bar is 0.5 μm.

FIG. 3B is an illustration of an exemplary extruded article formed fromthe as-cast Al alloy billet of FIG. 3A in accordance with variousaspects of the current technology. The scale bar is 1000 μm.

FIG. 4 is a flow diagram illustrating a method of forming an alloycomposition in accordance with various aspects of the currenttechnology.

FIG. 5 is a flow diagram illustrating a method of forming an extrudedarticle in accordance with various aspects of the current technology.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific compositions, components, devices, and methods, to provide athorough understanding of embodiments of the present disclosure. It willbe apparent to those skilled in the art that specific details need notbe employed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, elements, compositions, steps, integers, operations, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof. Although the open-ended term “comprising,” is tobe understood as a non-restrictive term used to describe and claimvarious embodiments set forth herein, in certain aspects, the term mayalternatively be understood to instead be a more limiting andrestrictive term, such as “consisting of” or “consisting essentiallyof.” Thus, for any given embodiment reciting compositions, materials,components, elements, features, integers, operations, and/or processsteps, the present disclosure also specifically includes embodimentsconsisting of, or consisting essentially of, such recited compositions,materials, components, elements, features, integers, operations, and/orprocess steps. In the case of “consisting of,” the alternativeembodiment excludes any additional compositions, materials, components,elements, features, integers, operations, and/or process steps, while inthe case of “consisting essentially of,” any additional compositions,materials, components, elements, features, integers, operations, and/orprocess steps that materially affect the basic and novel characteristicsare excluded from such an embodiment, but any compositions, materials,components, elements, features, integers, operations, and/or processsteps that do not materially affect the basic and novel characteristicscan be included in the embodiment.

Any method steps, processes, and operations described herein are not tobe construed as necessarily requiring their performance in theparticular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed, unless otherwiseindicated.

When a component, element, or layer is referred to as being “on,”“engaged to,” “connected to,” or “coupled to” another element or layer,it may be directly on, engaged, connected or coupled to the othercomponent, element, or layer, or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly engaged to,” “directly connected to,” or “directlycoupled to” another element or layer, there may be no interveningelements or layers present. Other words used to describe therelationship between elements should be interpreted in a like fashion(e.g., “between” versus “directly between,” “adjacent” versus “directlyadjacent,” etc.). As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various steps, elements, components, regions, layers and/orsections, these steps, elements, components, regions, layers and/orsections should not be limited by these terms, unless otherwiseindicated. These terms may be only used to distinguish one step,element, component, region, layer or section from another step, element,component, region, layer or section. Terms such as “first,” “second,”and other numerical terms when used herein do not imply a sequence ororder unless clearly indicated by the context. Thus, a first step,element, component, region, layer or section discussed below could betermed a second step, element, component, region, layer or sectionwithout departing from the teachings of the example embodiments.

Spatially or temporally relative terms, such as “before,” “after,”“inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and thelike, may be used herein for ease of description to describe one elementor feature's relationship to another element(s) or feature(s) asillustrated in the figures. Spatially or temporally relative terms maybe intended to encompass different orientations of the device or systemin use or operation in addition to the orientation depicted in thefigures.

Throughout this disclosure, the numerical values represent approximatemeasures or limits to ranges to encompass minor deviations from thegiven values and embodiments having about the value mentioned as well asthose having exactly the value mentioned. Other than in the workingexamples provided at the end of the detailed description, all numericalvalues of parameters (e.g., of quantities or conditions) in thisspecification, including the appended claims, are to be understood asbeing modified in all instances by the term “about” whether or not“about” actually appears before the numerical value. “About” indicatesthat the stated numerical value allows some slight imprecision (withsome approach to exactness in the value; approximately or reasonablyclose to the value; nearly). If the imprecision provided by “about” isnot otherwise understood in the art with this ordinary meaning, then“about” as used herein indicates at least variations that may arise fromordinary methods of measuring and using such parameters. For example,“about” may comprise a variation of less than or equal to 5%, optionallyless than or equal to 4%, optionally less than or equal to 3%,optionally less than or equal to 2%, optionally less than or equal to1%, optionally less than or equal to 0.5%, and in certain aspects,optionally less than or equal to 0.1%.

In addition, disclosure of ranges includes disclosure of all values andfurther divided ranges within the entire range, including endpoints andsub-ranges given for the ranges.

Example embodiments will now be described more fully with reference tothe accompanying drawings.

In order to decrease costs and reduce the C footprint associated withextruding 6000 series Al alloys having a low Fe content (generally lessthan or equal to about 0.15 wt. %) made from primary Al, Al scrap can beused to replace at least a portion of the primary Al. Currently, therecycled content by mass of 6000 series Al alloys is only about 10 wt. %to about 30 wt. % and only pre-consumer Al scrap from manufacturingprocesses is utilized. In order to reduce the C footprint associatedwith Al extrusions, applying post-consumer Al scrap (e.g., used beveragecans) is required as the volume of pre-consumer Al scrap is limited andcannot satisfy demand. However, post-consumer Al scrap has a high Fecontent of greater than about 0.15 wt. % in Al alloys, which isundesirable for certain applications, such as for extruded articles forautomobiles.

The high Fe content can generate intermetallic compounds, also referredto as “intermetallic phases” (having a longest diameter of greater thanor equal to about 1μm), that initiate cracks and decrease fatiguestrength, ductility, and fracture toughness. For example, FIG. 1 is anillustration showing a cross-section of an exemplary as-cast 6000 seriesAl alloy billet 10 having a high Fe content. The as-cast 6000 series Alalloy billet 10 includes a first intermetallic phase 12 composed ofMg₂Si, a second intermetallic phase 14 composed of α-AlFeSi, and a thirdintermetallic phase 16 composed of β-AlFeSi. The first intermetallicphase 12 dissolves during a homogenization heat treatment followingcasting. The second and third intermetallic phases 14, 16, which remainin products following extrusion from the as-cast 6000 series Al alloybillet 10, cause products extruded from the as-cast 6000 series Al alloybillet 10 to be susceptible to cracking. Even though they are importantfor dispersoid formation during homogenizing heat treatments, elevatedlevels of Cr and Mn, such as in 6082 Al alloys, also contribute to theformation of intermetallic phases comprising Fe.

Accordingly, the current technology provides an alloy composition formedfrom Al scrap, such as post-consumer Al scrap, that is substantiallyfree of intermetallic phases comprising Fe, has good mechanicalproperties, and can be processed with a lower C footprint relative toprimary Al alloys.

The alloy composition comprises Si at a concentration of greater than orequal to about 0.5 wt. % to less than or equal to about 1.5 wt. % orgreater than or equal to about 0.7 wt. % to less than or equal to about1 wt. %, such as at about 0.5 wt. %, about 0.6 wt. %, about 0.7 wt. %,about 0.8 wt. %, about 0.9 wt. %, about 1 wt. %, about 1.1 wt. %, about1.2 wt. %, about 1.3 wt. %, about 1.4 wt. %, or about 1.5 wt. %.

The alloy composition also comprises Mg at a concentration of greaterthan or equal to about 0.5 wt. % to less than or equal to about 1.5 wt.% or greater than or equal to about 0.7 wt. % to less than or equal toabout 1 wt. %, such as at about 0.5 wt. %, about 0.6 wt. %, about 0.7wt. %, about 0.8 wt. %, about 0.9 wt. %, about 1 wt. %, about 1.1 wt. %,about 1.2 wt. %, about 1.3 wt. %, about 1.4 wt. %, or about 1.5 wt. %.

The alloy composition also comprises Zr at a concentration of greaterthan or equal to about 0.1 wt. % to less than or equal to about 0.2 wt.% or greater than or equal to about 0.12 wt. % to less than or equal toabout 0.17 wt. %, such as at about 0.1 wt. %, about 0.11 wt. %, about0.12 wt. %, about 0.13 wt. %, about 0.14 wt. %, about 0.15 wt. %, about0.16 wt. %, about 0.17 wt. %, about 0.18 wt. %, about 0.19 wt. %, orabout 0.2 wt. %.

The alloy composition also comprises Fe at a concentration of greaterthan or equal to about 0.2 wt. % to less than or equal to about 0.4 wt.%, such as at about 0.2 wt. %, about 0.225 wt. %, about 0.25 wt. %,about 0.275 wt. %, about 0.3 wt. %, about 0.325 wt. %, about 0.35 wt. %,about 0.375 wt. %, or about 0.4 wt. %. At least a portion of the Fe isprovided by Al scrap, as discussed in more detail herein.

The alloy composition optionally includes Cr and Mn at individual andindependent concentrations of greater than or equal to about 0 wt. % toless than or equal to about 0.3 wt. %, greater than or equal to about0.05 wt. % to less than or equal to about 0.3 wt. %, or greater than orequal to about 0.1 wt. % to less than or equal to about 0.25 wt. %, suchas at 0 wt. %, about 0.05 wt. %, about 0.06 wt. %, about 0.07 wt. %,about 0.08 wt. %, about 0.09 wt. %, about 0.1 wt. %, about 0.11 wt. %,about 0.12 wt. %, about 0.13 wt. %, about 0.14 wt. %, about 0.15 wt. %,about 0.16 wt. %, about 0.17 wt. %, about 0.18 wt. %, about 0.19 wt. %,about 0.2 wt. %, about 0.21 wt. %, about 0.22 wt. %, about 0.23 wt. %,about 0.24 wt. %, about 0.25 wt. %, about 0.26 wt. %, about 0.27 wt. %,about 0.28 wt. %, about 0.29 wt. %, or about 0.3 wt. %. When both of theCr and Mn are present in the alloy composition, they have a combinedconcentration that is less than or equal to about 0.45 wt. %, i.e., acombined concentration of greater than about 0.05 wt. % to less than orequal to about 0.45 wt. %.

The alloy composition also optionally comprises Cu at a concentration ofgreater than or equal to about 0 wt. % to less than or equal to about 1wt. % or greater than or equal to about 0.1 wt. % to less than or equalto about 0.5 wt. %, such as at 0 wt. %, about 0.1 wt. %, about 0.2 wt.%, about 0.3 wt. %, about 0.4 wt. %, about 0.5 wt. %, about 0.6 wt. %,about 0.7 wt. %, about 0.8 wt. %, about 0.9 wt. %, or about 1 wt. %.

The alloy composition also optionally comprises Ti at a concentration ofgreater than or equal to about 0 wt. % to less than or equal to about0.2 wt. %, such as at 0 wt. %, about 0.05 wt. %, about 0.06 wt. %, about0.07 wt. %, about 0.08 wt. %, about 0.09 wt. %, about 0.1 wt. %, about0.11 wt. %, about 0.12 wt. %, about 0.13 wt. %, about 0.14 wt. %, about0.15 wt. %, about 0.16 wt. %, about 0.17 wt. %, about 0.18 wt. %, about0.19 wt. %, or about 0.2 wt. %.

The alloy composition also optionally comprises V at a concentration ofgreater than or equal to about 0 wt. % to less than or equal to about0.2 wt. %, such as at 0 wt. %, about 0.05 wt. %, about 0.06 wt. %, about0.07 wt. %, about 0.08 wt. %, about 0.09 wt. %, about 0.1 wt. %, about0.11 wt. %, about 0.12 wt. %, about 0.13 wt. %, about 0.14 wt. %, about0.15 wt. %, about 0.16 wt. %, about 0.17 wt. %, about 0.18 wt. %, about0.19 wt. %, or about 0.2 wt. %.

A balance of the alloy composition is Al. In various aspects, the Al ispresent at a concentration of greater than or equal to about 95 wt. %.

In various aspects, the alloy composition comprises, consistsessentially of, or consists of Si, Mg, Zr, Fe, Cr, Mn, Cu, Ti, V, andAl; Si, Mg, Zr, Fe, Mn, Cu, Ti, V, and Al; Si, Mg, Zr, Fe, Cr, Cu, Ti,V, and Al; Si, Mg, Zr, Fe, Cr, Mn, Ti, V, and Al; Si, Mg, Zr, Fe, Mn,Ti, V, and Al; Si, Mg, Zr, Fe, Cr, Ti, V, and Al; Si, Mg, Zr, Fe, Cr,Mn, Cu, V, and Al; Si, Mg, Zr, Fe, Mn, Cu, V, and Al; Si, Mg, Zr, Fe,Cr, Cu, V, and Al; Si, Mg, Zr, Fe, Cr, Mn, Cu, Ti, and Al; Si, Mg, Zr,Fe, Mn, Cu, Ti, and Al; Si, Mg, Zr, Fe, Cr, Cu, Ti, and Al; Si, Mg, Zr,Fe, Cr, Mn, V, and Al; Si, Mg, Zr, Fe, Mn, V, and Al; Si, Mg, Zr, Fe,Cr, V, and Al; Si, Mg, Zr, Fe, Cr, Mn, Cu, and Al; Si, Mg, Zr, Fe, Mn,Cu, and Al; Si, Mg, Zr, Fe, Cr, Cu, and Al; Si, Mg, Zr, Fe, Cr, Mn, Ti,and Al; Si, Mg, Zr, Fe, Mn, Ti, and Al; Si, Mg, Zr, Fe, Cr, Ti, and Al;Si, Mg, Zr, Fe, Cr, Mn, and Al; Si, Mg, Zr, Fe, Mn, and Al; Si, Mg, Zr,Fe, Cr, and Al; Si, Mg, Zr, Fe, Cu, Ti, V, and Al; Si, Mg, Zr, Fe, Ti,V, and Al; Si, Mg, Zr, Fe, Cu, V, and Al; Si, Mg, Zr, Fe, Cu, Ti, andAl; Si, Mg, Zr, Fe, Cu, and Al; Si, Mg, Zr, Fe, Ti, and Al; Si, Mg, Zr,Fe, V, and Al; or Si, Mg, Zr, Fe, and Al. As used herein, the term“consists essentially of” means that although no other component isintentionally added to the alloy composition, unavoidable impurities maybe included, for example, at individual and independent concentrationsof less than or equal to about 0.5 wt. %.

Greater than or equal to about 60% of the alloy composition is derivedfrom post-consumer Al scrap, such as from Al beverage cans, Alarchitectural components (e.g., Al window frames), or other scrap Almaterial. The post-consumer Al scrap provides the above-described Felevels, which are higher than the Fe levels found in 6000 series Alalloy extrusions provided for automotive purposes.

In some aspects, the alloy composition is in the form of a billet, e.g.,a log casted from an alloy melt.

The as-cast billet has a reduced content, i.e., at least about 20%reduced content, of intermetallic phases comprising Fe and at least oneof Si, Cr, Mn, or Al (also referred to as a “Fe-bearing intermetallicphase”) relative to a comparative as-cast 6082 Al alloy billet that hasthe same or substantially the same (e.g., within about 0.1% or about0.05%) Fe content. Fe interacts with Si and Al to form intermetallicphases during casting. Cr and Mn atoms in a melt can substitute for Featoms in Fe-bearing intermetallic phases during a casting process toform an Al(Fe,M)Si intermetallic phase, where M is Cr and/or Mn.Therefore, by keeping the concentrations of Cr and Mn low, i.e., to theconcentrations described herein, and including Zr, the content ofintermetallic phases comprising Fe in the alloy composition can bereduced or minimized. Table 1 shows comparative Al alloys havingrelatively high and low concentrations of Fe. This table shows that whenthe Fe content is lowered from 0.25 wt. % to 0.13 wt. %, the molefraction of Fe-containing intermetallic phases decreases substantially,where the mole fractions are determined computationally using athermodynamic-based model. However, the low Fe-containing Al alloy isassociated with a high C footprint. In the alloy composition of thecurrent technology (last row of Table 1), which includes at least about60% post-consumer Al scrap, the mole fraction of Fe-containingintermetallics decreases substantially (by greater than 20%) when Zr isincluded and the combined concentration of Cr and Mn is decreasedrelative to the high Fe-containing Al alloy. Therefore, by reducing acombined content of Cr and Mn and including Zr, the alloy compositionretains a high strength and exhibits excellent resistance to cracking.Beneficially, the alloy composition has a much lower C footprintrelative to the low Fe-containing Al alloy made from a primary Alcasting.

TABLE 1 Exemplary compositions and corresponding mole fractions ofintermetallic microstructures comprising Fe. Mole fraction of Si Mg ZrCr Mn Fe Al Fe-intermetallics Low [Fe] Al alloy 0.85 wt. % 0.8 wt. % —0.13 wt. % 0.45 wt. % 0.13 wt. % balance 0.76% High [Fe] Al alloy 0.85wt. % 0.8 wt. % — 0.13 wt. % 0.45 wt. % 0.25 wt. % balance 1.08% Alloycomposition 0.85 wt. % 0.8 wt. % 0.13 wt. %  0.2 wt. %  0.2 wt. % 0.25wt. % balance 0.79%

For extruded articles, such as automobile components, having highstrength and crash performance requirements, Cr and Mn can be includedto promote precipitation of dispersoids comprising Al(Fe, M)Si, where Mis Cr and/or Mn, during homogenization heat treatment conducted on theas-cast billet. As such, the as-cast billet comprises dispersoidsembedded within a matrix defined by the alloy composition. Thedispersoids are nanoparticles having diameters, i.e., average longestdiameters, of greater than or equal to about 30 nm to less than or equalto about 100 nm. Similarly, Zr enables precipitation of dispersoidscomprising Zr and at least one of Si or Al, e.g., (Al, Si)₃Zrnanoparticles. Therefore, in some aspects, the alloy compositioncomprises a first dispersoid comprising, consisting essentially of, orconsisting of Si, Fe, Al, and at least one of Cr or Mn; a seconddispersoid comprising, consisting essentially of, or consisting of Zrand at least one of Si or Al; or a combination thereof.

The alloy composition is suitable to be extruded into an extrudedarticle. When extruded, the alloy composition has a unique deformedmicrostructure in the absence of recrystallization that defines afibrous structure as the presence of the dispersoids impedesrecrystallization of the deformed microstructure. For example, FIG. 2Ais an illustration of an exemplary comparative as-cast Al alloy billet20 having dispersoids 22 embedded within a matrix 24. FIG. 2B is anillustration of an exemplary comparative extruded article 26 formed fromthe comparative as-cast Al alloy billet 20. Because the comparativeas-cast Al alloy billet 20 has a low volume of dispersoids, thecomparative extruded article 26 has a recrystallized microstructurehaving a large grain size, e.g., about 500 μm, defining a non-fibrousstructure. In contrast, FIG. 3A is an illustration of an as-cast billet30 comprising the alloy composition of the current technology and havingdispersoids 32 embedded within a matrix 34. FIG. 3B is an illustrationof an extruded article 36 formed from the as-cast billet 30. Here, theas-cast billet 30 has a sufficiently high enough volume of dispersoidsthat the extruded article 36 has a unique fibrous structure withelongated lamella aligned in the extrusion direction.

The extruded article can be a vehicle component or an architecturalcomponent, as non-limiting examples. Non-limiting examples of vehiclesthat have components suitable to be produced with the alloy compositioninclude automobiles, motorcycles, bicycles, boats, tractors, buses,mobile homes, campers, gliders, airplanes, and military vehicles, suchas tanks. In various aspects of the current technology, the extrudedarticle is an automobile part selected from the group consisting of abeam, a bumper, a floor pan, a battery enclosure, a wheel, a rocker, acontrol arm, a rail, a reinforcement panel, a step, a subframe member, apillar, and a strut. Therefore, the current technology also provides anautomobile part or other extruded article comprising the alloycomposition. The extruded articles exhibit a yield strength of greaterthan or equal to about 280 MPa when pulled along an extrusion directionduring tensile testing, an elongation to fracture of greater than orequal to about 8%, and a bending angle at maximum load of greater thanor equal to about 100/√{square root over (t)}° based on the VDA238-100bending test (sample size of 60 mm×60mm×t mm; punch radius of 0.4 mm;bending line perpendicular to the extrusion direction).

With reference to FIG. 4 , the current technology also provides a method40 for forming the alloy composition as a log billet 41. The method 40comprises forming a melt by melting post-consumer Al scrap, such as fromAl beverage cans 42, scrap Al window frames 44, and/or other Al scrap46. The post-consumer Al scrap includes a higher Fe content than most6000 series Al alloys. The method 40 then comprises adding at least oneprimary Al ingot 48 and at least one master alloy ingot (not shown) tothe melt to form an alloy melt, wherein the at least one master alloyingot provides Si, Mg, and Zr and at least one of Cr, Mn, Cu, Ti, or V.The at least one primary Al ingot 48 and/or the at least one masteralloy ingot may also provide a portion of the Fe. The alloy meltincludes the primary Al ingot 48 at a concentration of less than about40 wt. % based on the total mass of the alloy melt (i.e., the alloy meltincludes greater than or equal to about 60 wt. % post-consumer Al scrap)and each additional element at predetermined concentrations within theindividual elemental ranges described herein. The method 40 furtherincludes casting the alloy melt in a direct-chilled tooling to form acasted alloy composition and solidifying the casted alloy composition toform the log billet 41 including the composition described above.

With reference to FIG. 5 , the current technology also provides a method50 for forming an extruded article 52, which is depicted as a bumperbeam, as a non-limiting example. The method 50 comprises subjecting thelog billet 41, casted as discussed with reference to FIG. 4 , to ahomogenization heat treatment process comprising heating the log billet41 at a rate of greater than or equal to about 1° C./min to less than orequal to about 10° C./min until the log billet 41 reaches a temperatureof greater than or equal to about 500° C. to less than or equal to about580° C., maintaining the alloy composition at the temperature forgreater than or equal to about 0.5 hours to less than or equal to about24 hours, and fan or mist quenching the alloy composition. Thehomogenization heat treatment causes dispersoids to precipitate asdiscussed above. Moreover, the homogenized log billet 41 has a reducedcontent of intermetallic phases comprising Fe relative to a comparative6082 Al log billet having the same Fe content.

The method 50 then comprises heating the log billet 41 to a temperatureof greater than or equal to about 450° C. to less than or equal to about550° C. or greater than or equal to about 470° C. to less than or equalto about 500° C. to form a heated log billet 41. The heating can beperformed, for example, by heating the log billet 41 in a furnace.

After the heating, the method 50 comprises extruding the heated logbillet 41 through a die to form a heated extruded article. The diecomprises a slit that matches a cross-sectional geometry of the articlebeing made. As such, the heated extruded article has a cross-sectionalgeometry defined by the die. The extruding is performed by pushing thealloy composition through the die with a ram at a ram speed of greaterthan or equal to about 4 inches per minute (ipm) to less than or equalto about 20 ipm or greater than or equal to about 7 ipm to less than orequal to about 10 ipm.

Next, the method 50 comprises quenching the heated extruded article toform the extruded article 52. The quenching is performed at a rate fastenough to avoid formation of undesirable precipitates, but not too fastthat cracks or distortions are generated. Therefore, the quenchingcomprises lowering the temperature of the heated extruded article toambient temperature at a rate of greater than or equal to about 0.05°C./s or greater than or equal to about 1° C./s. The quenching isperformed by any method that is capable of cooling at the above rates,such as by contacting the heated extruded part with water or cold watermist.

The method then optionally comprises aging the extruded article 52. Theaging comprises heating the extruded article 52 to a temperature ofgreater than or equal to about 120° C. to less than or equal to about250° C., greater than or equal to about 130° C. to less than or equal toabout 200° C., or greater than or equal to about 175 ° C. to less thanor equal to about 185° C., such as at a temperature of about 120° C.,about 125° C., about 130° C., about 135° C., about 140° C., about 145°C., about 150° C., about 155° C., about 160° C., about 165° C., about170° C., about 175° C., about 180° C., about 185° C., about 190° C.,about 195° C., about 200° C., about 205° C., about 210° C., about 215°C., about 220° C., about 225° C., about 230° C., about 235° C., about240° C., about 245° C., or about 250° C. The aging is performed for atime of greater than or equal to about 0.5 hours to less than or equalto about 20 hours, greater than or equal to about 1 hour to less than orequal to about 10 hours, or greater than or equal to about 4 hours toless than or equal to about 8 hours, such as for about 0.5 hours, about1 hour, about 1.5 hours, about 2 hours, about 2.5 hours, about 3 hours,about 3.5 hours, about 4 hours, about 4.5 hours, about 5 hours, about 6hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours,about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15hours, about 16 hours, about 17 hours, about 18 hours, about 19 hours,or about 20 hours. The extruded article 52 is subsequently quenched.

In various aspects of the current technology, the method 50 alsoincludes at least one of prior to the aging, stretching the extrudedarticle 52 to improve the straightness of the extruded article 52; priorto or after the aging, discarding a portion from each end of theextruded article 52 because the extruded article 52 has a discard lengthof less than or equal to about 5 inches, less than or equal to about 2.5inches, or less than or equal to about 1 inch; cutting the extrudedarticle 52 to a desired size (for example, it is envisioned that aplurality of objects can be cut to form a length of the extruded article52); etching the extruded article 52; anodizing the extruded article 52;or further processing the extruded article 52, such as by bending ordenting into a desired shape.

Forming the extruded article 52 results in a reduction of at least about50%, at least about 70%, or at least about 90% of CO₂ equivalentsrelative to a corresponding method performed with a primary Al alloy andwithout post-consumer Al scrap. In some aspects, the method generatesabout 10 tons, about 5 tons, or about 3 tons CO₂ emission per 1 ton ofthe alloy composition extruded.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. An alloy composition comprising: silicon (Si) ata concentration of greater than or equal to about 0.5 wt. % to less thanor equal to about 1.5 wt. %; magnesium (Mg) at a concentration ofgreater than or equal to about 0.5 wt. % to less than or equal to about1.5 wt. %; zirconium (Zr) at a concentration of greater than or equal toabout 0.1 wt. % to less than or equal to about 0.2 wt. %; iron (Fe) at aconcentration of greater than or equal to about 0.2 wt. % to less thanor equal to about 0.4 wt. %; chromium (Cr) at a concentration of greaterthan or equal to about 0 wt. % to less than or equal to about 0.3 wt. %;manganese (Mn) at a concentration of greater than or equal to about 0wt. % to less than or equal to about 0.3 wt. %; copper (Cu) at aconcentration of greater than 0 wt. % to less than or equal to about 1wt. %; titanium (Ti) at a concentration of greater than 0 wt. % to lessthan or equal to about 0.2 wt. %; vanadium (V) at a concentration ofgreater than 0 wt. % to less than or equal to about 0.2 wt. %; and abalance of the alloy composition being aluminum (Al).
 2. The alloycomposition according to claim 1, comprising: the Si at a concentrationof greater than or equal to about 0.7 wt. % to less than or equal toabout 1 wt. %; the Mg at a concentration of greater than or equal toabout 0.7 wt. % to less than or equal to about 1 wt. %; and the Zr at aconcentration of greater than or equal to about 0.12 wt. % to less thanor equal to about 0.17 wt. %.
 3. The alloy composition according toclaim 1, comprising at least one of: the Cr at a concentration ofgreater than or equal to about 0.05 wt. % to less than or equal to about0.3 wt. %; or the Mn at a concentration of greater than or equal toabout 0.05 wt. % to less than or equal to about 0.3 wt. %.
 4. The alloycomposition according to claim 3, comprising: the Cr at a concentrationof greater than or equal to about 0.1 wt. % to less than or equal toabout 0.25 wt. %; and the Mn at a concentration of greater than or equalto about 0.1 wt. % to less than or equal to about 0.25 wt. %, whereinthe combined concentration of the Cr and the Mn is less than or equal toabout 0.45 wt. %.
 5. The alloy composition according to claim 1, whereinthe alloy composition further comprises: a first dispersoid comprisingZr and at least one of Si or Al; and a second dispersoid comprising Si,Fe, Al, and at least one of Cr or Mn, wherein the first and seconddispersoids have individual diameters of greater than or equal to about30 nm to less than or equal to about 100 nm.
 6. The alloy compositionaccording to claim 1, wherein the alloy composition includes a reducedamount of intermetallic phases comprising Fe relative to a comparative6082 alloy composition having substantially the same Fe concentration.7. The alloy composition according to claim 1, wherein greater than orequal to about 60% of the alloy composition is derived frompost-consumer Al scrap.
 8. The alloy composition according to claim 1 inthe form of a billet or a log.
 9. The alloy composition according toclaim 7 in the form of an extruded article having a fibrous structuredefined by the alloy composition.
 10. The alloy composition according toclaim 9, wherein the extruded article is an automobile part selectedfrom the group consisting of a beam, bumper, a floor pan, a batteryenclosure, a wheel, a rocker, a control arm, a rail, a reinforcementpanel, a step, a subframe member, a pillar, and a strut.
 11. The alloycomposition according to claim 9, wherein the extruded article has ayield strength of greater than or equal to about 280 MPa and anelongation to fracture of greater than or equal to about 8%.
 12. Amethod of forming an extruded article, the method comprising: heating abillet comprising an alloy composition to a temperature of greater thanor equal to about 450° C. to less than or equal to about 550° C. to forma heated billet; extruding the heated billet through a die to form aheated extruded article; and quenching the heated extruded article toform the extruded article, the extruded article having a fibrousstructure defined by the alloy composition, wherein the alloycomposition comprises: silicon (Si) at a concentration of greater thanor equal to about 0.5 wt. % to less than or equal to about 1.5 wt. %;magnesium (Mg) at a concentration of greater than or equal to about 0.5wt. % to less than or equal to about 1.5 wt. %; zirconium (Zr) at aconcentration of greater than or equal to about 0.1 wt. % to less thanor equal to about 0.2 wt. %; iron (Fe) at a concentration of greaterthan or equal to about 0.2 wt. % to less than or equal to about 0.4 wt.%; chromium (Cr) at a concentration of greater than or equal to about 0wt. % to less than or equal to about 0.3 wt. %; manganese (Mn) at aconcentration of greater than or equal to about 0 wt. % to less than orequal to about 0.3 wt. %; copper (Cu) at a concentration of greater than0 wt. % to less than or equal to about 1 wt. %; titanium (Ti) at aconcentration of greater than 0 wt. % to less than or equal to about 0.2wt. %; vanadium (V) at a concentration of greater than 0 wt. % to lessthan or equal to about 0.2 wt. %; and a balance of the alloy compositionbeing aluminum (Al).
 13. The method according to claim 12, whereingreater than or equal to about 60% of the alloy composition is derivedfrom post-consumer Al scrap.
 14. The method according to claim 12,wherein the alloy composition comprises: a first dispersoid comprisingZr and at least one of Si or Al; and a second dispersoid comprising Si,Fe, Al, and at least one of Cr or Mn, wherein the first and seconddispersoids have individual diameters of greater than or equal to about30 nm to less than or equal to about 100 nm.
 15. The method according toclaim 12, wherein the extruding is performed with a ram at a ram speedof greater than or equal to about 4 inches per minute to less than orequal to about 20 inches per minute.
 16. The method according to claim12, wherein the quenching is performed by water mist at a cooling rateof greater than or equal to about 0.05° C./s.
 17. The method accordingto claim 12, further comprising aging the extruded article by heatingthe extruded article to a temperature of greater than or equal to about120° C. to less than or equal to about 250° C. for a time of greaterthan or equal to about 0.5 hours to less than or equal to about 20hours.
 18. The method according to claim 12, wherein, prior to theheating, the alloy composition is subjected to a homogenization processcomprising: heating the billet at a rate of greater than or equal toabout 1° C./min to less than or equal to about 10° C./min until thealloy composition reaches a temperature of greater than or equal toabout 500° C. to less than or equal to about 580° C.; maintaining thealloy composition at the temperature for greater than or equal to about0.5 hours to less than or equal to about 24 hours; and quenching thealloy composition.
 19. The method according to claim 12, wherein themethod generates less than or equal to about 10 tons of carbon dioxide(CO2) emission per 1 ton of the extruded article that is formed.
 20. Amethod of forming an alloy composition, the method comprising: forming amelt by melting post-consumer aluminum (Al) scrap; adding at least onemaster alloy ingot to the melt, wherein the at least one master alloyingot provides silicon (Si), magnesium (Mg), zirconium (Zr), chromium(Cr), manganese (Mn), copper (Cu), titanium (Ti), and vanadium (V);adding at least one primary Al ingot to the melt to form an alloy melt,wherein the alloy melt includes the primary Al ingot at a concentrationof less than about 40 wt. % based on the total mass of the alloy melt;casting the alloy melt in a direct-chilled tooling to form a castedalloy composition; and solidifying the casted alloy composition to formthe alloy composition, wherein the alloy composition comprises: Si at aconcentration of greater than or equal to about 0.5 wt. % to less thanor equal to about 1.8 wt. %; Mg at a concentration of greater than orequal to about 0.5 wt. % to less than or equal to about 1.5 wt. %; Zr ata concentration of greater than or equal to about 0.05 wt. % to lessthan or equal to about 0.2 wt. %; iron (Fe) at a concentration ofgreater than or equal to about 0.2 wt. % to less than or equal to about0.4 wt. %; Cr at a concentration of greater than or equal to about 0 wt.% to less than or equal to about 0.3 wt. %; Mn at a concentration ofgreater than or equal to about 0 wt. % to less than or equal to about0.3 wt. %; Cu at a concentration of greater than 0 wt. % to less than orequal to about 1 wt. %; Ti at a concentration of greater than 0 wt. % toless than or equal to about 0.2 wt. %; V at a concentration of greaterthan 0 wt. % to less than or equal to about 0.2 wt. %; and a balance ofthe alloy composition being Al.